Accession Number : ADA200268

Title :   Scanning Electron Microscopic Study of In Vitro Toxicity of Ethylene Oxide Sterilized Bone Repair Materials.

Descriptive Note : Interim rept. Jul 87-Mar 88,

Corporate Author : ARMY INST OF DENTAL RESEARCH WASHINGTON DC

Personal Author(s) : Zislis, Theodore ; Mark, Deiren E ; Martin, Steven A ; Cerbas, Emeterio L ; Heath, James R

PDF Url : ADA200268

Report Date : 15 Aug 1988

Pagination or Media Count : 23

Abstract : Polylactic acid (PLA) and polyglycolic acid (PGA) have been under investigation for use in the management of hard and soft tissue wounds. Current research has included the incorporation of osteoinductive substances into a PLA-PGA copolymer allocplastic implant material for enhancing the healing of osseous defects. Conventional methods of sterilization such as dry heat, steam heat or cobalt 60 radiation, tend to either destroy or attenuate osteoinductive activity and alter polymer degradation. Ethylene oxide (EO) gas sterilization is currently being tested as an alternate method. This study examined the relationship of EO-induced cytotoxicity to the length of time of polymer aeration following EO sterilization. Three groups of copolymer implant discs were studied: (1) 50:50 PLA-PGA copolymer, (2) PLA-PGA polymer with hydroxyapatite (HA) and (3) PLA-PGA with autolyzed, antigen--extracted (AA) bone particles. SEM examination revealed changes in cell growth with increasing periods of aeration suggestive of increasing cell vitality. Cells growing on discs having no aeration were small, round and lobulated; whereas those of seven to fourteen days of aeration were more numerous, and flattened with many microvilli, pseydopodia, and dentritic processes, features consistent with normal cell morphology. These results suggest that EO sterilized polymer implants should be aerated at least seven to fourteen days prior to surgical use. (aw)

Descriptors :   *COPOLYMERS, *ETHYLENE OXIDE, *TOXICITY, *ARTIFICIAL TISSUE, ACIDS, AERATION, BONES, CELLS(BIOLOGY), DEGRADATION, DISKS, ELECTRON MICROSCOPY, ELECTRONIC SCANNERS, ELECTROOPTICS, GASES, GLYCOLIC ACID, HEALING, HEAT, SURGICAL IMPLANTATION, IN VITRO ANALYSIS, LACTIC ACID, LOW HUMIDITY, MATERIALS, MORPHOLOGY(BIOLOGY), PARTICLES, POLYMERS, SOFT TISSUES, STEAM, STERILIZATION, WOUNDS AND INJURIES, OSTEOGENESIS

Subject Categories : Toxicology
      Medical Facilities, Equipment and Supplies
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE